The present invention relates to a fuel injector for use with an internal combustion engine, and more particularly to a fuel injector improved in fuel atomization.
Conventionally, there have been proposed various types of fuel injectors intended to improve fuel atomization and thereby improve combustibility of fuel in a combustion chamber of the internal combustion engine.
For example, Japanese Utility Model Laid-open Publication No. 55-71063 discloses a fuel injector having a needle valve formed at its end with an expanded portion for atomizing fuel. However, as a fuel injection hole in this fuel injector is defined around the needle valve, an annular opening area of the fuel injection hole is vary small, causing plugging of the fuel injection hole due to a foreign matter in the fuel.
Another type fuel injector is disclosed in Japanese Utility Model Laid-open Publication No. 57-152458, for example. This fuel injector is provided with an obstacle as a fuel colliding member at a position downstream of a fuel injection hole, so that the fuel injected from the fuel injection hole may collide with the obstacle to improve fuel atomization. However, it is technically difficult to locate the obstacle in alignment with the fuel injection hole, causing an increase in manufacturing cost.